| 摘要 |
<p>PURPOSE:To eliminate the limitation of an exposure control range based upon the aperture control limit of a lens by using photometric outputs before on- course stopping operation and after interruption of stopping in specific relation with stop-down control operation or shutter control operation. CONSTITUTION:A switch (S)3 is placed selectively at the side of a terminal 201 in program mode and the aperture ring of a lens is set to a maximum aperture value corresponding to a minimum aperture. When a shutter release button is pressed to the 1st stage, an SM is closed and a photodiode PD receives light passed through the lens and aperture to charge a capacitor (C)1 through an amplifier OP1. When the shutter release button is further pressed, an S1 is opened before stopping operation and a program signal for aperture determination is stored in the C1. When the shutter release button is furthermore pressed, outputs of amplifiers OP1 and OP2 are compared with each other by a comparator CP1; the stopping operation is ceased through an electromagnet Mg1 and that is stored in the C2. The voltage of the C2 is applied to a comparator CP3 and also controls an electromagnet Mg2 together with a signal from a trigger S4 to control the shutter speed.</p> |
